Código:
  
  protected void processRequest(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException, ClassNotFoundException { 
            
            String I,N,D,M;
            response.setContentType("text/html;charset=UTF-8");
            PrintWriter pw=response.getWriter();
            String url = "jdbc:mysql://localhost:3306/escuela";
            String usuario = "root";
            String contraseña = "ravilion1";
            Connection con = null;      
            
        try {
            pw.println("Hola1");
            Class.forName("com.mysql.jdbc.Driver");
            con = DriverManager.getConnection(url, usuario , contraseña);
            Statement st = con.createStatement();
        
            
            pw.println("<table border='1';style='width:75%'>");
            java.sql.ResultSet rs;
            rs=st.executeQuery("Select * from Alumnos");
            
            while( rs.next() ){
                pw.println("Hola2");
                I=rs.getString("Id_Alumno");
                N=rs.getString("Nombre");
                D=rs.getString("Domicilio");
                M=rs.getString("Id_Materia");
                
                pw.println(" <tr>");
                pw.println(" <th>"+I+" </td>");
                pw.println(" <th>"+N+"</td>");
                pw.println(" <th>"+D+"</td>");
                pw.println(" <th>"+M+"</td>");
                pw.println(" </tr>");
            }
            pw.println("</table>");
            
        } catch (SQLException ex) {
            Logger.getLogger(ConsultaAlmuno.class.getName()).log(Level.SEVERE, null, ex);
        }
    }
 

